Fluid coupling



ay 26, 1942. Q BREER ETAL l 2,28423 FLUID COUPLING Filed April 25, 1941 y 2 Shets-Sheet l ATTORN EY5.

May 269 w42. c. BREER ETAL FLUID COUPLING Filed April 25, 1941 2 Sheets-Sheet 2 l l ATTORNEY Patented May 26, 1.942

FLUID COUPLING Carl Breer, Grosse Pointe, and Gordon R. Pennington, Bloomfield Hills, Mi

ch., asslgnors to Chrysler Corporation, Highland Park, Mich., a

corporation of Delaware Application Aprll25, 1941, Serial No. 390,3/02

20 Claims.

This invention relates to power transmission for use with motor vehicles or other machines or devices where it is desired to provide a cushioned drive or a transmission of power under varying torque converting conditions.

It is an objection of ourinvention to provide a power transmission embodying a multiplestage fluid drive of improved characteristics and eiilciency of operation.

Another object is yto provide an improved fluid coupling of the type embodying an impeller structure and -a plurality of runner structures, the runner 'structures automatically operating successively to impart drive to the vehicle as the vehicle or other load comes up to predetermined speed. Fluid couplings of such type may be termed multiple-stage couplings as distinguished from the more common type of coupling wherein the fluid circuit operates between an impeller and a single runner. l

A further object of our invention is to provide improved operating eiliciency in multiple-stage couplings especially when operating above the torque multiplying or converting range when it is desired to provide a minimum of slip between the impeller and the plurality ofv runners Further objects and advantages of our. invention reside in the novel construction and relationship of parts more particularly hereinafter set forth, reference being had to the accompanying drawings in which:

Fig. 1 is an elevational view showing our power transmission arranged for driving a motor vehicle. l

Fig. 2 is a sectional elevational view through the fluid coupling and gearing. l

Fig. 3 is a detail view of a portion of the primary runner structure taken as indicated by line 3-3 of Fig. 2.

Fig. 4 is a detail sectional viewvthrough typical vanes of the Fig. `3 runner, the view being taken as indicated by line 4-4 of Fig. 3.

Fig. 5 is a detail sectional view through other portions of the vanes shown in Figs. 3 and 4, the view being taken as indicated by line 5-5 of Fig. 3.

Fig. 6 is an elevational view of a portion of the secondary runner structure taken according to line 6 6 of Fig. 2.

Fig. 7 is a diagrammatic view of velocity vectors for the coupling members, the view being taken as indicated by line 'l-l of Fig. 2.

Fig. 8 is a view corresponding to Fig. 5 but illustrating a modified vane formation.

1 Fig. 9 is a view corresponding to Fig. 4 but illustrating a further modified vane formation.

Referring to the drawings we -have illustrated our power transmission in connection with a motor vehicle drive wherein ,A represents the usual engine, B the casing for uid coupling C, and D a transmission of any desired type.

Secured to the rear end of the engine crankshaft I0 is the flywheel shrouding II which extends rearwardly to carry the impeller structure. I2 which is of heml-torus formation. This impeller or driving member I2 of the uid coupling comprises the annular dish-shaped housing I3 opening axially forwardly and having a plurality of radially extending circumferentiallyspaced vanes I4 preferably of non-curving or planar formation similar to the vanes I5 of the secondary runnerstructure I6 as shown in Fig. 6.

The secondary runner I6 has its dish-shaped hemitorus housing I'l forwardly closed so as to be open axially rearwardly facing the open portion of impeller I2. vDisposed intermediate the impeller I2 and runner I6 is a primary runner structure I8 having its vanes I9 arranged in circumferentially spaced relationship and disposed generally radially between inner and outer cylindrical housings 20 and 2I respectively. 'I'he vane passages of runner I8 are axially open to the vane passages of impeller I2 and runner I6 and, according to known practice, the vanes may differ in number in the component impeller and runner structures for elimination of hydraulic pulsations. Any desired number of primary runners may be interposed between impeller I2 and runner I6 for connection-throughsuitable gearing according to the showing in the patent to H. F. Patterson No. 2,203,177 of June 4, 1940.

In order to illustrate the principles of operation of our coupling we have shown runner I6 connected to a hub 22 mounted on driven shaft 23 and journalled by ball bearing 24 in the structural extension 25 of crankshaft I 0, this extension mounting the shrouding I I.

Runner I8 is connected to a hubl 26 having a 4^ sleeve portion 26n journalled by anti-friction bearings 21, 28 on shaft 23 and carrying a sun gear 29 meshing with the large planetary pinion 30. This pinion has formed therewith a smaller pinion 3| meshing with a sun gear 32 larger than sun gear 28 and fixed -to shaft 23. The carrier 33 for the compound planet pinions 30, 3| has a rear cylinder portion 34 /journalled by ball bearing 35 on shaft 23 and formed with the usual cam faces for coaction with one-way brake rollers 38 disposed within cylindrical portion 31 of fixed housing B. The one-way brake E is so arrangedas to allow carrier 33 to rotate freely forwardly in the direction of rotation of crank-shaft I8 but to prevent rotation of the carrier in the opposite direction.

Shaft 23 is journalled by a ball bearing 38 carried by the forward end of transmission D and has a pinion 39 meshing with countershaft gear 48 formed with a cluster gear 4I. The output shaft 42, which transmits drive to the usual rear ground wheels of the vehicle, has splined connection with a gear 48 formed with clutch teeth 44 engageable with teeth 45 of pinion 39.

` A reverse idler gear 48 is in constant mesh with gear 4I. A suitable shift mechanism 4l is provided to shift gear 43 from its illustrated position either forwardly to clutch teeth 44 with teeth 45, or rearwardly to mesh gear 43 with reverse idler 48. In the one instance shaft 42 will be directly coupled with shaft 23 and in the other instance shaft 42 willl receive a reverse reduction drive from shaft 23.

The fluid coupling is partially filled, according to known practice. with suitable fluid such as coupling oil, seals 48, 48 being 'provided to prevent escape of the oil. The various vanes I4, I5, and I9 are preferably welded or hydrogen brazed with their respective carrying shells or housings I3, I1 and 28, 2I. Before describing our novel formation of vanes I8lwe will briefly describe the operation of the arrangement as thus far described.

For forward drive, gear 43 is shifted forwardly to clutch with teeth 45 and the engine A is speeded up in the usual manner thereby causing fluid in the coupling to bedisplaced at impeller I2 toward primary runner I8 adjacent the outer regions of their vane passages. Inasmuch as shaft 42 is under load, the secondary runner I8 tends,-to"remain stationary and the uid will, for the most part, set up a circulatory path as generally indicated at F-G. This circulation is facilitated by the arrangement of the vane passages of runner I8 which are radially freely open. Runner I8 therefore takes over the drive from impeller I2 and rotates forwardly at relatively slow but increasing speed, the slip between the impeller I2 and runner I8 being accommodated by the oil.

Forward rotation of runner I8 drives sun 29 and, as shaft 28 tends to remain stationary under its load, carrier 33 tends to rotate backwards causing brake E to hold the carrier with casing B. This compels shaft 23 to `turn forwardly with torque multiplication at the train 29, 38, 3I, 32, brake E taking the reaction. As the car is accelerated from rest, with accompanying increase in speed of runner I8 and runner I 8,

' the circuit F-G enlarges so as t'c cause runner I8 to take over the drive. At such time the fluid circuit may be generally represented as F-H-J-K. The transition is of course of a gradual nature. When runner I8 is the principal driving element, then runner I8 idles around and assumes more and more of the drive as the car is accelerated from rest. Then when runner I8 is the principal driving element, runner I8 idles around and brake E releases to permit barrier 33 to rotate lforwardly with only slight slip between shaft 23 and sleeve 28a. After the torque multiplying range has been passed, the coupling structures I2, I8, I8 should desirably perform much as an ordinary twopartuid coupling of the type having an impeller and juxtaposed runner but the presence of the runner I8 in the type of coupling illustrated introduces certain disadvantages and inefiiciencies which are largely overcome by our invention. The condition of drive through the coupling above the torque multiplying range may be referred to as the locked condition of the coupling during the vehicle cruising range although it will be understood that there will always be a hydraulic slip between impeller I2 and runner I8 and also between runner I8 and runner I8.

During the locked condition, runner I8 rotates slower than runner I8, the latter rotating slower than impeller I2. Therefore the oil returning from runner I8 to runner I8 along the inner part of circuit F--H-J-K would tend to slow down or impede rotation of runner I8 against its rotational tendency by reason of the oil forced from impeller I2 to rlmner I8 along the outer part of this circuit. During the locked condition a certain amount of the oil travels radially inwardly of the passages formed by vanes I8, as indicated at circuit portion G. and this flow accelerates runner I8 because the tangential velocity of the oil has to slow down, the difference being imparted as energy to runner I8.

It will be apparent that, from a standpoint of energy balance, the fluid energy at delivery or transfer zone 5I must equal the fluid energy at transfer or delivery zone 58 plus the fluid energy at the inward flow along vanes I8 as at G plus energy given up to runners I8 and I8. During cruising, any energy transferred to runner I8 at zones 58, 5I is lost because runner I8 is free at such time from drive connection with shaft23. Therefore minimizing energy transferred at zone 58 from runner I8 to runner I8 will result in less energy loss and an increase in operating efliciency.

'inasmuch as runner I8 rotates faster than runner I8 during cruising or locked condition of drive; it will be apparent that the oil delivered at zone 58 to runner I8 will approach this runner at an angle with respect to a line 52 (Fig. 7) parallel to the axis of rotation of the coupling ,structures and extending through zone 58. Fig.

7 diagrammatically illustrates portions of the coupling elements at zone 58 during cruising conditions. At this time the tangential velocities of the members I2, I8 and I8 may be vectorially represented at 53. 54 and 55 assuming about 1/2 of 1% slip between members l2 and I8 and something of the order of 2 to 3% slip between members I8 and I8. The latter slip is represented by the vector difference 56 and we therefore incline the portions of vanes I8 adjacent zone 58 so that the angle of approach of these vane portions with respect to line 52 is substantially equal to the travel of the uid at zone 58 thereby to compensate for the difference in speeds of members I8 and I8 so that the iiuid will enter the vane passages of runner I3 with a minimum of disturbance of the fluid flow and with a minimum of circumferential impact on vanes I8 and so that the fluid in travelling through runner I8 will be allowed to follow its natural directional flow with a minimum of disturbance, the outer ends of vanes I8 being planar and radial as seen in Fig. 4. Actually, because of unavoidable hydraulic losses, the effect of the fluid travel relative to speed difference 58 will be somewhat less than this vector difference and may be represented at 51 which distance determines the amount of warping of the inner ends of vanes I8 adjacent zone 58.

In practice the vanes I8 are progressively warped starting from about midway vof their radial lengths at region 58 so that at approximately the region of maximum uid ilow at zone 50 the vanes I9 have inclined approach portions 58 lying generally in a direction so as not to interfere with the natural ow direction of iluid iromv runner I8. We find that the approach portions, if inclined about 35, will provide good results in keeping with the desired objects. If desired, these inner warped vane portions may have a continuous constant angle of around 35 with respect to line 52 as shown in Fig. '7A but in order to impart greater rigidity to the runner I8, and for other reasons herein set forth, the discharge portions of the warped vane portions may have a different inclination from the approach portions 59 as shown in Figs. 5 and 7 or they may be parallel to line 52 as in Fig. 8.

As there is less speed difference between runner I8 and impeller I2, represented bythe difference in vectors 53 and 54. the corresponding directional oil travel at zone 58 will be at an angle less than at zone 58. Therefore the discharge end portions of vane portions 59 are formed at 6I) of less axial angularity than at 59 so as to cause the iluid to leave the'runner I8 at zone 58 at approximately the angle for admission to the vane passages of impeller I2 with a minimum of energy loss, the general angularity at 68 being about In practice the inner portions of vanes I9 may be generally curved as in Fig. 5 so as to provide smooth fluid ow without abrupt change in direction and for minimizing hydraulic losses. However, if desired, the entrance portions may be formed flat at an angle of about 35 as at 58* in Fig. 8 and discharge portions 80 axial.

By reason of our invention the energy loss in the main circuit F-H-J-K during cruising or locked driving condition is minimized and the eiilciency of the coupling increased. Furthermore, by imparting angularity to vanes I8 at their inner end portions, the runner I8 is thereby reinforced and made rigidespecially with respect to tendency of ring to move circumferentially relative to ring 2| because of the oil ilow and inertia effects of these rings.

For reverse drive, the gear 43 is shifted rearwardly to mesh with idler 46. Coupling C functions just the same in driving the car in reverse as in the forward drive although ordinarily the reverse drive will be limited to the torque conversion range of operation unless the vehicle should be driven in reverse at a suillciently high speed to cause the runner I8 to take over the major share of drive from runner I8.

During the torque conversion drive, iluid which extends beyond circuit F-G into runner I6 and circuit F-HJ-K will, of course, serve to drive runner I 8 forwardly and thereby supplement the drive imparted by runner I8 through gearing 38, 3| to shaft 28. Under starting load circuit F-G will predominate over circuit F-H-Jf-K but as the speeds of runners I8 and I6 increases circuit F-H-J-K gradually becomes predominant over circuit F-G and eventually runner I8 takes over the full drive to shaft 23, a small quantity of iluid ilowing in circuit F-G as aforesaid. The warping of vane I8, as at 59, 68, will not hinder radially inward ilow of fluid in runner I8.

1 Our arrangement anords beneficial inflow action of the iiuid in runners `I8 and I8. The oil travelling radially inwardly in runner I9v during the torque multiplying operation accelerates runner I8 because of the increasing change in the tangential velocity of the oil thereby imparting energy to the runner I8. In addition, the impact of the oil transferred at 5I to runner I8 also serves to supplement the drive of this runner. While we have shown impeller I2 and runner I8 free from the customary torus ring at the central zone of oil circulation, this is not as important as maintaining runner I8 free for oil travel radially inwardly so as to allow the inflow action of the oil to take place. I Referring to Fig. 9 we have illustrated a modiilcation of the arrangement in Figs. 3 and 4 wherein the vanes I9"` are warped below zone 58 Just as in Figs. 3and 4 but `above zone 58 these vanes are now disposed at a slight angle of approximately 5 to the axis. For general convenience of manufacture the upper angled portions of the vanes I8b above zone 58 are planar as in Fig'. 3, also for the reason that curving or warping the vanes at these upper portions would not make iuch appreciable difference over planar forma- When the coupling is operating above thel torque conversion range then, if runner I8 idies around at the same speed as that of impeller I2, there would be no circulation of the oil inwardly of runner I8 and the oil would circulate in path F-H-J-K. It is because of any diilerence in speed between structures I2 and I8 that the oil circulates to some extent in path F-G tending to bring runner I8 up to the speed of the impeller I2. However if the warped curved portions 59, 88 are properly designed then the relative rotation between members I2 and I8 becomes so slight that, for practical purposes, the outer portions of the vanes I 8 may be arranged planar and parallel to the axis as in Figs. 3 and 4. However, if it is desired to introduce a further refinement, especially where runner I8 tends to lag impeller I 2 under the assumed conditions, then the eillciency of the coupling may be further increased by disposing the outer portions of the vanes of runner I8 at a slight angle such as around 5 with the axis. The direction of inclination is the same as that at 58, but not so great in extent because there will be a much greater dierence between members I8 and I8 than between mem- Y bers I2 and I8.

In each of Figs. 5, 7A, 8 and 9 the inner portions of the vanes of runner I8 are of warped formation. In Figs..5 and 9 they are also inclined with the axis and also curved'in the axialv direction. In Fig. 8 the warped vane surfaces are inclined at their entrance portions 59EL and straight or parallel with the axis at their discharge portions 68B. In Fig. 9 the outer end portions of these vanes are planar and slightly angled with respect to the axis.

The direction of inclination of the outer end inspeed the torque converting 50 of returning fluid flow in circuit F-H--J-K. In Figs. 5 and 9 this inclination is of changing or curving formation at I8, B0. In defining the circuits F-H-J-K and F-G according to the directional arrows in Fig. 2, it is of course assumed that the system is operating for normal drive of the vehicle by the engine as, during coast, the seccgidary runner Il becomes the driver orimpeller causing the oil to reverse its direction of flow.

The warped relationship of the inner end portions of the vanes of runner I8 is such that these portions are displaced about the general longitudinal or radial axis of these vanes relative to runner; said impeller and runners being disposed for rotation about a common axis and said primary runner` being disposed axially between said impeller and said secondary runner such that fluid in said coupling will flow in a circuit from said impeller through said primary runner to said secondary runner and thence returning through said primary runner to said impeller; said primary runner having a plurality of vanes extending outwardly from said axis and defining passages accommodating flow of s aid fluid in said circuit and also in a second circuit from said impeller to said primaryrunner and thence inwardly along said vane passages for return to said impeller; means providing a releasable driving connection between said primary runner and said driven shaft for multiplying torque between said primary runner and said driven shaft during fluid flow in said second circuit thereby providing one stage of operation of said coupling, said releasa-ble driving connecting means operating automatically to release said primary runner from driving connection with said driven shaft during fluid flow in the first said circuit to allow said secondary runner to drive said driven shaft independently of said primary runner and to allow said primary runner to coast around with said impeller thereby providing another stage of operation of said coupling; said vanes of said primary runner having inner portions thereof warped with respect to outer portions thereof to dispose said inner portions angularly with respect to lines parallel to said axis at the zone of returning fluid flowing in the rst said circuit from said secondary runner to said primary runner, the inclination of said vane inner portions adjacent said zone being such that the fluid from said secondary runner will enter the vane portions of said primary runner with minimized disturbance of the fluid flow and with minimized circumferential impact of the fluid on the vanes of said primary runner when said coupling is operating in its said another stage.

2. In a power transmission; a power input shaft adapted to deliver power during rotation thereof in a given direction; a driven output shaft; a multi-stage fluid coupling for trans- 'mitting drive from said driving shaft to said driven shaft; said coupling comprising a vaned impeller adapted to receive drive from said driving shaft, a Vvaried secondary runner adapted to transmit drive to .said driven shaft. and a vaned primaryrunner; said impeller and runners beingv disposed for rotation about a common axis and said primary runner being disposed axially between said impeller and said secondary runner such that uid in said coupling will flow in a circuit from said impeller through said primary runner to said secondary runner and thence returning through said primary runner to said impeller; said primary runner having a plurality of vanes extending outwardly from said axis and dening passages accommodating ow of said fluid in said circuit and also in a second circuit from said impeller to said primary runner and thence inwardly along said vane passages for return to said impeller; means providing a releasable driving connection between said primary runner and saiddriven shaft for multiplying torque between said primary runner and said driven shaft during uid flow in said second A circuit thereby providing one stage of operation of said coupling, said releasable driving connecting means operating automatically to release said primary runner from driving connection with said driven shaft during fluid ow in the rst said circuit to allow said secondary runner to drive said driven shaft independently of said primary runner and to allow said primary runner to coast around with said impeller thereby providing another stage of operation of said coupling; said vanes of said primary runner having fluid-receiving inner portions thereof disposed angularly with respect to lines parallel to said axis at the zone of returning uid owing in the first said circuit from said secondary runner to said primary runner, the inclination of said vane inner portions adjacent said zone being such that the fluid from said secondary runner will enter the vane portions of said primary runner with minimized disturbance of the fluid flow and with minimized circumferential impact of the fluid on the vanes of said primary runner when said coupling is operating in its said another stage.

3.A In a power transmission according to claim 2; the inclination of said vane inner portions adjacent said zone being in excess of approximately 30 with respect to said parallel lines.

4. In a powe'r transmission according to claim 2; portions of said vane inner portions in the region of fluid discharged therefrom in the rst said circuit being disposed at an inclination with respect to said parallel lines, this inclination being less than that of said vane inner portions adjacent said zone.

5. In a power transmissionl according to claim 1; portions of said vane warped inner portions disposed in the region of fluid discharged therefrom in the first said circuit being disposed at an inclination with respect to'said parallel lines, this inclination being less than that of said vane inner portions adjacent said zone.

6. In a power transmission according to claim v 2; portions of said vane inner portions in the region of fluid discharged therefrom in the first ture between said outer and inner regions, thev that of said vane inner portions adjacent said zone.

8. In a power transmission according to claim 2; portions of said vane inner portions in the region of uid discharged therefrom in thdrst said circuit being disposed approximately parallel with said parallel lines.

9. In a power transmission according to claim 1; portions of said vane warpedinner portions disposed in the region of fluid -discharged therefrom in the rst said circuit being disposed approximately parallel with said parallel lines.

10. In a power transmission according to claim 1; said outer portions of the vanes of said primary runner being substantially planar.

11. In a power transmission according to claim l 2; said vanes of said primary runner having outer substantially planar portions thereof disposed in the rst said circuit.

12. In a power transmission according to claim 1; said outer portions of the vanes of said primary runner having uid-receiving portionsV thereof inclined with respect to lines parallel to said axis at the zone of uid flowing from said impeller in the iirst said circuit.

13. In a power transmission according to claim 2; said vanes of said primary runner having outer uid-receiving portions thereof inclined with respect to lines parallel to said axis at the zone of :duid owing from said impeller in the first said circuit.

14. In a power transmission according to claim 2; the vanes of said impeller and secondary runner being substantially planar.

15. In a power transmission according to claim 1; the vanes of said impeller and secondary runner being substantially planar.

16. In a uid coupling; vaned co-axial relatively rotatable impeller and runner members of approximately hemitoroidal formation; an intermediate vaned runner structure rotatable about said axis relatively to each of said members and disposed axially therebetween; the

vanes of said intermediate runner structure be-- ing disposed to form passages therebetween open toward said members and extending generally outwardly with respect to said axis so as to accommodate iiuid now between said members by passage of the uid through said intermediateA runner structure at inner and outer regions respectively adjacent inner and outer ends of said passages and to accommodate uid now inwardly within said intermediate runner structure between said outer and innerregions, the vanes of said intermediate runner structure having portions adjacent said inner regions warped with respect to portions thereof adjacentsaid outer regions.

17. In a fluid coupling; vaned co-axial relatively rotatable impeller and runner members of approximately hemitoroidal formation; an intermediate vaned runner structure rotatable about said axis relatively to each of said members and disposed axially therebetween; the vanes ot said intermediate runner structure being disposed to form passages therebetween open toward said members and extendinggenerally outwardly with respect to said axis so as to accommodate nuid now between said members by passage oi the fluid through said intermediate runner structure at inner and outer regions respectively adjacent inner and outer ends of said passages and to accommodate iiuid now inwardly within said intermediate runner strucvanes of said intermediate runner structure having portions thereof adjacentsaid inner regions. disposed angularly with respect to llines parallelto said axis atthe zone of uid flowing 'from said Y runner member toward said intermediate run-v ner structure.

18. In afluid coupling; vaned co-axial relatively rotatable impeller and runner members of approximately hemitoroidai formation; anin- 1 termediate vaned runner structure rotatable;

about said axis relatively to each of said members and disposed axially therebetween; the vanes. of said intermediate runner structurebeing disposed to form passages therebetween open vtoward said members and extending generally outwardly with respect to said axis so as to accommodate fluid flow between said members by passage of the uid through said intermediate runner structure at inner and outer reg-ions respectively adjacent inner and outer ends of said passages and to accommodate iiuid now inwardly within said intermediate runner structure between said outer and inner regions, the vanes of said intermediate runner structure having portions thereof adjacent said inner regions disposed angularly with respect to lines parallel to said axis at the zone of fluid owing from said.

runner member toward said intermediate runnei structure, the inclination of said angularly disposed vane portions being less adjacent the extremities thereof which discharge fluid from said passages toward said impeller member at said inner regions than adjacent the extremities thereof which admit fluid to said passages from said runner member at said inner regions.

19. In a fiuid coupling; vaned co-axial relatively rotatabie impeller and runner members of approximately hemitoroidal formation; an intermediate vaned runner structure rotatable about said axis relatively to each of said members and disposed axially therebetween; the vanes of said intermediate runner structure being disposed to form passages therebetween open toward said members and extending generally outwardly with respect to said axis so as to accommodate iluid flow between said members by passage of the nuid through said intermediate runner structure at inner and outer regions respectively adjacent inner and outer ends of said passages and to accommodate iiuid now inwardly within said intermediate runner structure between said outer and inner regions. the vanes of said intermediate runner structure having portions thereof adjacent said inner regions warped in relation to portions of these vanes adjacent lsaid outer regions. and in relation to lines parallel to said axis at the zone of fluid Iflowing from said runner member toward said l other; a plurality of circumferentiallyspaced vanes extending between said rings to denne a plurality of passages accommodating iiuid now through the runner structure adjacent each of said rings and also inwardly within the runner structure from said outer ring'to said inner ring; said vanes having inner with respect to outer portions thereof.

oAar. nanna. GORDON n. PENNmGToN.

portions thereof warped 

